1. Field of the Invention
The present invention relates to a tape cartridge for accommodating a long printing tape on which a desirable series of characters are printed, a ribbon cartridge for accommodating an ink ribbon used for printing on the printing tape, and a printing device for detachably receiving the tape cartridge and the ribbon cartridge and printing the desirable series of characters on the printing tape.
2. Description of the Related Art
A printing tape generally accommodated in a tape cartridge is detachably and replaceably set in a printing device for printing a desirable series of letters and characters on the printing tape. Such a tape cartridge generally includes a mechanism for holding a long tape on a cylindrical tape core and feeding a required amount of the tape out of the tape core so as to efficiently accommodate the long tape and smoothly feed the tape to the printing device.
The printing device used with such a tape cartridge has a cutting mechanism for cutting the long tape to be desirable length. The cutting mechanism is typically arranged near a tape outlet to allow the long tape to be cut any desirable position through operation of a lever or the like.
An ink ribbon consumed for printing a desirable series of characters on a sheet or tape is also accommodated in an ink ribbon cartridge, which is detachably and replaceably set in the printing device. Such an ink ribbon cartridge generally includes a mechanism for holding a long ink ribbon on a cylindrical ink ribbon core and winding a used ink ribbon on a ribbon winding core so as to compactly accommodate the long ink ribbon and smoothly feed the ink ribbon to the printing device. Both the ink ribbon core and the ribbon winding core are formed to be rotatable via a driving mechanism formed in the printing device for driving and rotating the ink ribbon core and the ribbon winding core. This, the cartridge is not equipped the driving mechanism, effectively reduces the manufacturing cost of each expendable ink ribbon cartridge.
Under such a condition that the tape cartridge is not set in a printing device, the tape core unintentionally starts rotation due to some vibration or shock to press an end of the tape into a cartridge case. The end of the tape incidentally entering the cartridge case is not easily removed.
Although the cartridge case is to be opened for removal of the tape stuck in the cartridge case, forcible opening of the cartridge case generally accommodating both the tape and the ink ribbon may slacken the ink ribbon or even move the ink ribbon from a predetermined position to damage the whole cartridge.
When the tape cartridge having one end of the tape pressed into the cartridge case is accidentally set in a printing device, the tape held and fed between a platen and a printing head is stuck in the tape cartridge to damage the printing device.
Another problem arises in the printing device; that is, when the user tries to use a cutting mechanism during printing operation, the tape is not smoothly fed but may be stuck in the printing device.
There is also a problem in the ribbon cartridge. The ink ribbon core is rotated through engagement with a driving shaft of a driving element formed in the printing device as mentioned above. The ink ribbon core not being set in the printing device is thus easily rotatable due to vibration or shock so as to slacken the ink ribbon. Slack of the ink ribbon damages an ink ribbon driving mechanism of the printing device or lower the printing quality.
A protective sheet or element for interfering with rotation of the ink ribbon core is separately inserted in the ink ribbon core before delivery. Alternatively, a special casing for preventing slack of the ink ribbon is used during delivery and storage of the cartridge. These methods, however, have the following problems.
In the former method, manufacturing and management process of the cartridge is rather complicated, and the user should remove the protective sheet before use of the cartridge. When the user sets the cartridge in the printing device without removing the protective sheet, it may cause damage of the ink ribbon driving mechanism of the printing device.
In the latter method, for example, one or a plurality of engagement pawls are formed in an inner face of a special case for ribbon cartridge. The engagement pawls engage with the ink ribbon core and interfere with rotation of the ink ribbon core. This requires an additional manufacturing and management process to raise the cost of the expendable cartridge.
In such a cartridge, the ink ribbon and the tape are held between the platen and the printing head. When the user forcibly pulls out the tape under non-printing conditions, the ink ribbon joints the tape to be pulled out of the cartridge according to the forcible movement of the tape.
One object of the invention is to prevent a tape from being pressed into and stuck in a cartridge case of a tape cartridge, thus making a printing device free from troubles due to the stuck tape.
Another object of the invention is to efficiently and securely prevent slack of an ink ribbon due to unintentional rotation of an ink ribbon core in an ink ribbon cartridge.
Still another object of the invention is to prevent an ink ribbon from being pulled out of a cartridge according to a forcible movement of a tape.
The above and other objects are realized by a tape cartridge including a cartridge case for accommodating a long printing tape freely fed out of the cartridge case for printing in response to operation of a printing device, and a mechanism for preventing an end of the printing tape from being reversely moved back into the cartridge case.
The tape cartridge of the invention further includes a tape core on which the long printing tape is wound. The tape core includes, as the reverse movement preventing mechanism, an anti-inversion mechanism for preventing rotation of the tape core in a reverse direction opposite to a feeding direction of the long printing tape for printing. In an alternative structure, the tape core has a flange element with an adhesive inner surface to be in contact with at least one of upper and lower sides of the long printing tape.
The anti-inversion mechanism for preventing reverse movement of the printing tape back into the cartridge case includes an engaging element uprightly formed on an outer face of a flange element of the tape core and an engagement element formed on the cartridge case to be located opposite to the engaging element of the tape core. In another structure, the anti-inversion mechanism includes an engagement member mounted on the cartridge case and an engaging element formed on the tape core to be located opposite to the engagement member of the cartridge case.
Engagement of the engagement member of the cartridge case with the engaging element of the tape core in the anti-inversion mechanism is released when the tape cartridge is set in the printing device. In a preferable structure, the anti-inversion mechanism allows rotation of the tape core in a normal direction identical with the feeding direction of the long printing tape for printing.
In another application of the invention, a tape cartridge includes a cartridge case for accommodating a long printing tape held between a platen and a printing head. The platen is installed in the cartridge case, which has a substantially elliptic aperture for movably receiving a shaft of the platen, and a fixed wall formed in a moving direction of the platen movably fitted in the aperture for holding the printing tape between the platen and the fixed wall. In this structure, a longitudinal axis of the elliptic aperture is located across a feeding direction of the printing tape. When the printing tape is moved to be back into the cartridge case, the platen moves to prevent the printing tape held between the platen and the fixed wall from being moved back into the cartridge case.
The cartridge case preferably includes a predetermined length of a guide element arranged near an outlet of the printing tape formed on the cartridge case and along a feeding path of the printing tape.
In still another application of the invention, a cartridge includes a cartridge case for accommodating a long printing tape and a long ink ribbon used for printing on the printing tape in a printing device. The cartridge includes a cylindrical ink ribbon core for holding the long ink ribbon thereon and a cylindrical ribbon winding core for holding a used ink ribbon wound thereon after printing in the printing device. The cartridge is detachably set in the printing device. The ink ribbon core has an engaging element on a portion exposed under such a condition that the ink ribbon is wound on the ink ribbon core. The cartridge case rotatably supporting the ink ribbon core has an engagement piece to engage with the engaging element of the ink ribbon core to prevent rotation of the ink ribbon core.
A printing device according to the invention includes a cartridge holder unit for detachably receiving a cartridge with a printing tape accommodated therein. The printing tape accommodated in the cartridge is fed with an ink ribbon for printing. The printing device further includes a platen driving shaft engaging with a platen mounted on the cartridge and rotating the platen to feed the printing tape according to rotation of the platen driving shaft, a cutting mechanism for cutting the printing tape fed out of the cartridge according to the rotation of the platen driving shaft at a desirable position, a detection unit for detecting a movement of the cutting mechanism during the rotation of the platen driving shaft, and a stop mechanism for interrupting the rotation of the platen driving shaft when the movement of the cutting mechanism is detected by the detection unit.
In another application, a printing device includes a cartridge holder unit for detachably receiving a cartridge accommodating a printing tape and an ink ribbon core with an ink ribbon wound thereon and fed out of the cartridge for printing. The ink ribbon core has an engaging element formed on a portion exposed under such a condition that the ink ribbon is wound on the ink ribbon core. The cartridge has an engagement piece to engage with the engaging element of the ink ribbon core. The cartridge holder unit of the printing device includes an upright contact projection for being in contact with the engagement piece formed in the cartridge to move the engagement piece in a release direction for releasing the engagement of the engagement piece with the engaging element of the ink ribbon core when the cartridge is mounted on the cartridge holder unit.
In still another application of the invention, a printing device includes a cartridge holder unit for detachably receiving a cartridge accommodating a printing tape and a ribbon winding core with a used ink ribbon wound thereon after printing. The ribbon winding core has a second engaging element formed on a portion exposed under such a condition that the used ink ribbon is wound on the ribbon winding core. The cartridge has a second engagement piece to engage with the second engaging element of the ribbon winding core. The cartridge holder unit of the printing device includes a second upright contact projection for being in contact with the second engagement piece formed in the cartridge to move the second engagement piece in a release direction for releasing the engagement of the second engagement piece with the second engaging element of the ribbon winding core when the cartridge is mounted on the cartridge holder unit.
In another preferable structure of the invention, a printing device includes a cartridge holder unit for detachably receiving a cartridge accommodating a cylindrical ink ribbon core with a long ink ribbon wound thereon, a cylindrical ribbon winding core with the long ink ribbon wound thereon after being used for printing in the printing device, and a long printing tape on which a desirable series of characters are printed by an ink of the ink ribbon. The printing device further includes a printing head for adhesively holding the printing tape and the ink ribbon between a platen and the printing head, a driving unit for feeding the printing tape and rotating the ribbon winding core synchronously with the feed of the printing tape, and a ribbon winding core driving unit for rotating the ribbon winding core according to a pull-out movement of the printing tape under non-printing conditions.
The driving unit of the printing device preferably includes a stepping motor functioning as a driving source, a first transmission mechanism for transmitting rotation of the stepping motor to the platen, and a second transmission mechanism diversified at a predetermined point from the first transmission mechanism for transmitting the rotation of the stepping motor to the ribbon winding core. The ribbon winding core driving unit preferably includes a one-way clutch arranged between the stepping motor and the predetermined point of the first transmission mechanism for interfering with transmission of rotation from the platen.
These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings.